The field of aluminum can crushing is a crowded art. The prior art discloses a vast number of different approaches to crushing aluminum cans ranging from hand crushers for use by the consumer in the home or business to very large industrial crushers for use in recycling yards which handle millions of cans in any given month. Included within the prior art are many kinds of cans of intermediate capacity for crushing cans one at a time but automatically. One such device is disclosed in U.S. Pat. No. 4,573,405 to Morlock, Mar. 4, 1986 and a similar concept is disclosed by Baumgartner, U.S. Pat. No. 5,095,815, Mar. 17, 1992. These two devices are, to the best of the applicant's knowledge the most closely related prior art.
Morlock, U.S. Pat. No. 4,573,405 discloses a crusher that comprises a vertically oriented rotatable drum, which is an idler drum driven by the crusher, in which is mounted a crushing roller. The crushing roller, which is power driven, and which drives the drum, is a metal cylindrical structure having ribs on the exterior positioned such that a nip is formed between the inner surface of the drum and the outer surface of the crusher, the nip being capable of opening against a resilient bias. The structure of the drum and the crusher requires that the crusher be made of a very strong material, e.g., a metal such as steel. One of the problems with this kind of a device generally is that aluminum has a very high propensity to gall and tends to jam the crusher as the aluminum cans are crushed and are retained on the surface of the crusher or the drum, or fragments are collected on the drum or the crusher. Another problem is that the presence of ice, which accumulates in cold weather, or the presence of plastic or glass may prevent driving engagement of the drum by the roller and result in a jam rendering the entire device inoperable.
The Baumgartner invention, U.S. Pat. No. 5,095,815, is similar in most essential respects to the device of Morlock but incorporates projections on the interior of the drum and provides a scraper to try to keep the drum and the crusher clean of galled aluminum cans or aluminum fragments.
It is an object of this invention to overcome the jamming and galling problems of these prior art devices and other similar devices.
Another can crushing device is disclosed by Newman, U.S. Pat. No. 4,444,100, Apr. 24, 1984. This can crusher is similar in most respects to the devices previously described but is provided with a slide guide that directs the cans into the nip between the roller and the drum. This device suffers from the aluminum galling problem previously discussed.
Other can crushers are disclosed in U.S. Pat. No. 4,316,410 to Davis, Feb. 23, 1982, U.S. Pat. No. 3,776,128 to Morris, Dec. 4, 1973, U.S. Pat. No. 4,235,164 to Allen, et al., Nov. 25, 1980, U.S. Pat. No. 3,827,351 to Rosnow, Aug. 6, 1974 and to Malrsky, U.S. Pat. No. 3,036,517, May 29, 1962. These latter devices use mechanisms quite different from those previously discussed.
Interestingly, fruit crushers are known to use a generally similar arrangement of a rotating drum with a rotating crusher roller mounted inside the drum. Obviously, the problems faced differ in crushing fruit than in crushing aluminum cans and the specific problem of galling of aluminum and jamming of the crushing mechanism is not present. Such crushers are disclosed, for example, in U.S. Pat. No. 4,355,473, to Berry, Aug. 26, 1982 and U.S. Pat. No. 1,655,333, to Perazio, Jan. 3, 1928.
The present invention overcomes the problems of the prior art by incorporating a number of features which work together in combination to result in a can crusher which is reliable and wherein there is originally no tendency to jam as a result of crushed cans or fragments of cans or aluminum buildup or the jamming of crushed cans in the mechanisms.